Abstract

We report the structural, magnetic, electrical transport properties, and magnetocaloric effect (MCE) of antipervoskite compound . It exhibits a second-order ferromagnetic–paramagnetic phase transition around 287 K. The electronic resistivity shows a good metallic behavior except for a slope change around . At lower temperatures (below 130 K), indicates that the electron-electron scatterings domain. At evaluated temperatures (130–270 K), is linear dependence on temperature, implying that the phonon scatterings boost up greatly. Furthermore, a broad distribution of the magnetic entropy change peak is found to about 100 K with the magnetic field change . The relative cooling power are and (or and ) with and 45 kOe, respectively. All these values are comparable with the typical MCE associated with a second-order transition. It suggests that may be considered as a candidate material for near room-temperature magnetic refrigeration because of: (i) the large full width at half peak of the curve, (ii) no hysteresis losses, (iii) the near room-temperature working temperature, and (iv) the low-cost and innoxious raw materials. Moreover, it is found that the simple theoretical model which only considering the magnetoelastic and magnetoelectronic couplings couldn’t account well for the observed MCE in antiperovskite .

Received 24 January 2010Accepted 25 September 2010Published online 11 November 2010

Acknowledgments:

This work was supported by the National Key Basic Research under contract No. 2007CB925002, the National Natural Science Foundation of China under Contract Nos. 50701042, 51001094, 10774146, and 10804111, and Director’s Fund of Hefei Institutes of Physical Science, Chinese Academy of Sciences under Contract No. O84N3A1133.